Automatic block-signal system.



No. 851.692. PATENTED APR. 30, 1907. P. P. J. PATBNALL & G. H. DRYDEN.

AUTOMATIC BLOCK SIGNAL SYSTEM.

APPLIOATIGN FILED DBO. 4. 1906.

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www M PATENTED APR. 30, 1907.

F. P. J. PATENALL & G. H. DRYDEN.`

AUTOMATIC BLOCK SIGNAL SYSTEM. APPLICATION FILED DBO. 4, 1906.

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Inventor/.s @L WM' ,692. PATENTED APR. 30, 1907.

F. P. J. PATENALL a G. H. DRYDEN.

AUTOMATIC BLOCK SIGNAL SYSTEM.

APPLICATION FILD DBO. 4. 1906.

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- ed out particularly more, Maryland, have invented certain new UNITEDSTATESMPATENT FFICE FRANK P. J. PATENALL AND GEORGE DRYDEN, OFBALTIMORE, MARYLAND.

AUTOMATIC BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented April 30, 1907.

Application tiled December 4, 1906. Serial Nu. 346,238.

United States, residing in the city of Baltiand useful Improvements inAutomatic Block-Signal Systems; and We do hereby declare the followingto be a full, clear, and eX- l act description of the same, referencebeing had to the accompanying drawings, forming a part of thisspecification, and to the figures andy letters ot reference markedthereon.

This` invention relates to automatic railway signaling systems beingmore especially though not exclusively applicable in connection withtrack circuits adapted to be shunted by the wheels and axles of a trainor the opening of switches, etc. in the track section forming the block.

The objects of the invention are especially to effect a more positive,efficient and economical operation of the signal motor mechanisms,indicators, etc. even under adverse climatic or weather conditions.Also'to provide a system not liable to be seriously affected bylightning discharges or the influx of heavy currents from extraneoussources. Also to provide a system wherein the signal lightsv will be socontrolled as to give `the highest efficiency and greatest economy, andas incidental thereto, to provide a system wherein the signal lightswill be automatically lighted only when necessary or desirable toindicate the condition of the signals, as for instance, when there isan'approaching train l in one of the .two preceding blocks or tracksections. Also to provide a system so arranged, that failure of the lineconnections between block or signal stations will still leave the systemoperative to permit a continuance of traffic with entire safety andiinder the control of properly operated signals normally included in thecomplete system.

The invention consists in certain novel details of construction andcombinations and arrangements of the circuits and circuit connectionsand appliances appurtenant thereto all as will be hereinafter describedand pointin the appended claims. l In the accompanying drawings-Figure 1is a diagrammatic illustration of a system embodying the presentimprovements and arranged for the `operation or control of threeposition signals, each having one semaphore arm and. one lamp. Figi 2 isa diagrammatic illustration of a portion of the system showing moreespecially the circuit arrangement for controlling or operating thedistant relay of each block or signal station. Fig. 3 1s a diagrammaticillustration of a system corresponding to the system illustrated inFigs. 1 and 2 but arranged for the operation or control of a pluralityof seinaphores and lam s or lights therefor, and from which it will eunderstood that any number of lights may be arranged in multiple andcontrolled from the saine circuit.

Similar letters of reference in the several figures indicate the saineparts.

In the system adopted for illustrating the present invention, traffic issu posed to proceed in one direction only, tiat is to say, from left toright as illustrated by the arrows in Figs. l and 2, although certainfeatures of the Asystem are equally applicable where t-rafiic is toproceed in both directions vover the same track, for instance, theautomatic lighting of the signal lights in advance of a train and theextinguishing of such lights after the passage of the train. ln bothFigs. l and 3 four signal or block stations are shown, t-lie circuitconnections of the first and last stations however being incomplete, butas will be readily understood by those skilled in the art, the portionsof the circuit connections and appliances not illustrated are merelyduplicates of the corresponding port-ioiis of the circuit connectionsand appliances shown in the intermediate. signal or block stations ofthe illustrations.

The block sections are indicated respectively, by the referencecharacters A A2 A3 and A4 and associated with each block section is ablock or signal station preferably located with the semaphore or signalmechanism at the entrance to the block, the semaphores or signals beingdiagrammatically illustrated as is customary at S ""2 S3 and S4respectively.

B B2 BSand B* are track batteries, or other source of low voltage power,preferably located in proximity to the exit end of the respective tracksections and adapted to energize track rela s T T2 T3 and acorresponding track relay, not illustrated, the relay T being energizedby a track battery, not illustrated, but forming a portion of the systemcorresponding to the portions illus- IOO trated as will be readilyunderstood. Short circuiting of the rails or tracks between thebatteries and track relays (le-energizes the latter and through ropercircuit connections controlled by said relays, 1n connection withcircuit connections controlled by the signals, the signals themselvesare operated to indicate to the engineer of each train, the trackconditions existing for two blocks in advance of that on which the trainis running and also operate or permit the signals in rear ot thetrain'to operate in a direction to indicate stop or danger.

The circuit connections and appliances may be briefly described asfollows: C C2 C3 and C* are clearing relays each controlled by twopreceding track circuit sections. D D2 D3 D4 are distant relays for thecontrol of the distant or clear indication of the. signals S etc., theserelays being normally energized, but not with sulicient power to attracttheir armatures, except when the next succeeding signal is in either theclear or caution osition. E E2 E3 E4 are double wound re ays, E beingincluded in series in a circuit with D2, E2 beingincluded in series in acircuit with D3 and E3 beinor included in a circuit in series with D,Eacli is controlled by two sections of track circuit, as will presentlyappear. l/ L2 L3 and L4 are signal lights or lamps each controlleddirectly by the clearing relays C etc. and the latter, as before stated,are controlled by two preceding track circuit sections whereby thesignal lights will be lighted to show the condition of the semaphores orsignals at two stations in advance of the train. F F2 F 3 and F 4 arebatteries or other source of power for the control of the line relays,switch and tower indicators, which latter Will be presently described. GG2 G3 and Gr4 are storage batteries from which power is derived forlighting the signal lights and operating the signal motors, signaloperating clutches, locks &c. The latter parts are well known in the artand are therefore not illustrated, the circuit connections leadingthereto being deemed sufficient for an understanding of the presentinvention. In this connection it may be stated that the controllingrelays shown, are applicable for controlling practically any of theknown systems of signal or semaphore operating motors, clutches, locks&c.

The 'storage batteries may be charged from a power circuit or fromprimary batteries or other suitable source of electrical energy andhence charging terminals are sim y indicated in the dlagram at W in thewel understood manner.

In connection with the main block si naling system itis ractical and'desirab e to make use of switcli indicators, switch lamps, towerindicators, crossing bells, etc. and these parts are illustrateddiagrammatically in the drawings, thus H H2 and H3 are switchindicators, each controlled from two track sections namely, theimmediate track section `as well as the preceding track section.Indicator I l2 is shown as an indicating relay carrying a local contactP for lighting switch lamp O from alocal storage battery I I2 and I3 areswitch instruments for short circuiting the rails when switches areopened. R indicates a crossing or Warning bell controlled by a towerindicator relay and supplied with power from a' battery V and it will beunderstood that the tower indicators U may give a visual indication totowermen, gatemen or station agents when trains are approaching.

N N2 N and N4 are circuit controlling (levices always open to break thecircuit when the semaphores or signals are at danger and closed by thesaid semaphores or signals when they reach the 45 or caution posltion toestablish the circuit. They are held closed when the semaphore or signalmoves to the clear or 90o position, thus the said circuit controllingdevices are always closed to establish the circuits when the signals arein both caution and clear positions but are open to break the circuitswhen the semaphores or signals are in danger position.

Referring particularly to Fig. '2 it will be seen that the relays E E2etc. are double wound relays, that is to say, the circuit mav beestablished througl'l all oi' the coils of said relay or a portion ofthe coils of said relavlnay be shunted or short circuited. This relay iswound to a high resistance, while the relay D2 in series therewith, iswound to a low resistance, the proportioning being such that when thecircuit flows through all of the coils oll the relay E the armature ofrelay D2 will not be attracted, but when the circuit is establishedthrough a portion only offthe coils ot' relay E', sufficient currentwill How through the circuit to attract the armature of relay D2 and`render the same'etfective for controlling a motor circuit as. willpresently appear. The shunt for the coils of the relay E' is controlledby the circuit controlling devices N etc. whereby the shunting iseffected by the semaphores or signals. To better illustrate theoperation` of the system a train is presumed to occupy the block sectionA4 as indicated at X, the signal 'or semaphore at the entranceto thenext succeeding section being at clear and the secondsucceedinvsemaphore or signal being atcaution, al other semaphores or signalsbeing at danger, but it being understood `that all sections in advanceof section A4 are unoccupied. Under these conditions, current frombattery F flows through the upper contact of track relay T, coils ofrelay E', line wire K2 intermediate contact of track relay T', distantrela D2 to common return Wire M thus ener'- gizing relay E to attractits armature, but the relay D2 being wound to a low resistance look IIO

its armature is not attracted. Current from battery F passing throughthe said upper contact of track rela T branches through front contact4of relay through wire J to a 5 clearing relay corresponding to relay Cbut at the next succeeding station, and therefore not shown, returningthrough common return wire M. At the block station for section A2, theconditions aresomewhat altered because of the fact that the semaphore orsignal is at caution and the circuit closing -device N2 closed. At thisstation, current frombatte F2 flows through the upper contact of tracrelay ated by signal S2 and closed because the latter isincautionposition, through a part of the resistance in relay E2, to linewire K3, intermediate contact on track relay T2, coils of relay D3 tocommon return wire M, a suffi- 'zo cient current flowing in thisinstance because of the shunt at E2 to cause the armature of the relayD3 to be attracted, the conditions then existin being that the armaturesof both relays 2, D3 are attracted and the circuit connectionscontrolled thereby established. Current from battery F2 passing throughthe upper contact of track relay T' and branching through relay E2passes to circuit wire J2 and energizes switch indicator H and relay Cin le with each other, the return beiii/gr I lO multip effectedv throughthe common' return wire At the signal station for the block A3 thesemaphore S3 is at clear position and the cir- 3 5 cuit from the batteryF3 passing throughthe u per contact of track re ay T2, circuit closerNx3 on signal S3, throu h a part of the coils of relay E3 to line wire 2thence to intermediate contact on track relay T3, finds the latter openbecause of the short circuiting of the track battery B3 and no currentows. As la result relays E3 and D2 are de-energized and their 'armaturesdown. The branch of the circuit from the battery F3 controlled by therelay E3 bein opened by the dropping of the armature of t e relay E3, nocurrent ows on the line J 3 and as a result switch indicator H2 andclearing relay C2 of the succeeding stati on are de-energized, switch-indicator H2 displaying danger, and through the back contaetat Plighting the switch lamp O. Relay C2 operates throughv suitable frontand back contacts to perform several functions. First the dropping ofthe armature opens the front :contact to remove the shunts from thesignal motor as will be presently explained. Seeondly it gives currentfrom the storage battery through its upper back contact, lower -lirontcontact oftraek relay T to caution motor control Z through motor (notshown) y and back to-battery through the return motor control Z therebyvdrivin the signal S2 to the caution position. Tnir ly it gives current'from the 'storage battery through the lower back contact to the lamp orsignal light L2 Icurrent to the back T, circuit closer N2 oper the frontcontact of thereby lighting the lamp for signal-S2 which latter is nowin the caution position and illuminated. Relays T3and E4 beingcle-energized no .current passes from battery F4 to the switch indicatorH3, tower indicator U or clearing relay C3. Indicator H3 therefore goesto danger by gravity, tower indicating relay U assumes danger positionby gravity and gives contact of its armature to the crossing bell andopens to perform the removing the shunt secondly, giving curfrom thebattery V the armature of relay C3 three functions of first, from thesignal motor, rent'through its upper back contact and also front contactof track relay T2 to caution motor control Z through the motor and backto battery thereby driving the signal S3 to caution position. Signal S2as well as signal S3 now being in caution position and circuitcontroller N2 closed shunting a part of the resistance of relay E2, thecurrent in line K3 isof sufficient strength to attract the armature ofdistant relay D3. Signal S3 having already been driven to the cautionposition, we now have circuit conditions for permitting current fromstorage battery G3 to pass through upper back contact of relay C, lowerfront contact of track relay T2, branching through front contact ondistant -relay D3 to clear motor control Z2 and through said motordriving the signal to its clear position. Thirdly, current from storagebattery G3 finds a path through lower back contact of clearing relay C3to lamp L3 whereby the latt'er is li hted to illuminate the -signal S3.With train X occupying the' block section A* and the track relay T3 oien, a following train entering track section or the next sectionpreceding thesection A3 causes the clearing relay C2 to open, currentbeing immediately given to light the lamp L2, although signal S2 cannotoperate on account of track relay T3 being open and hence the dangerconditions ahead of the following train are indicated both by t ieposition signal. nder the i-llustrated'conditions t. e., witha trainoccupying block section A, it will also be noted that signal lam'is L2and L3 and switch lamp O are burning but lamys L and L4 are not lighted,signal S2 is in the caution position and signal S3 in the clearposition, switch indicators H2 H3 at the danger, switch indicator H isclear, tower indicator U is at danger and crossing bell li is caused toring. It will be noted that all track relays T, T etc. are so arrangedthat when energized they are in position to permit current to passthrough the4 lower front contacts from the storage batteries to the whendeenergized the home or caution control side of the signal motor is inshunt with the return motor control through the lower back contact. Theshunting of the distant or clear motor control side of the signal motorsor clutches is controlled by the duplicate front and the lighting of theA IOO Y from the signal motor for signal S.

Vthereby causing the indicator H" danger by contacts of the relays C',C3, C3, C3 both said shunts being effective at all times save when themotor or motors are being operated to move or hold the signals. Theshunt circults may be clearly seen in Fig. 1 at the left hand station A3where the clear motor control Z3 leads directly to one of the duplicatefront contacts of the relay C4 and said relay C4 being energized theshunt circuit is cornleted through its armature and the other rontcontact of relay C3 to the motor control return Z. From the cautionmotor control Z the shunt is established through the armature andl backcontact of track relay T3. This relay being denergized Aand its armatureagainst said contact establishes the shunt circuit to the motor controlreturn 7. thus `both motor controls are shunted or short circuited. WhentrainK passesinto block section A3 and out of block section A, trackbattery B3 is short circuited, thereby causing the track relay T3 to bede-energized, (the signal or semaphore S3 immediately assuming thedanger iosition) and opens the circuit through fine wire K3(le-energizing relays D3 and E3 and cau-sing their armatures to drop.The dro i ping of the armature of the relay E3 opens t e circuit throughthe line wire J3 to go to gravity and the armature of clearing relay Cto drop and remove the shunt Storage battery G through the back contactof relay C lights the signal light L, operates the motor to move thevsignal S to caution, and the latter through the circuit controller Nshunts a part of the resistance in relay E to increase the current inline K3, the effect of which is to cause the armature ofv relay D3 to beattracted giving current from the storage battery G3 to the clear motorcontrol and thereby changing the signal S3 toihe clear position. Trackrelay T3 closes as the train moves ourl of the section'A3 thereby givingcurrent from battery F3 through upper front contact of relay T3coils or"relay E3 to line K5 leading back to the track relay and distant relay ofthe preceding section not shown in the drawing, the return beingeffected through the common wire M and the result being to attract thearmature of relay E4 thereby giving the current through the frontcontact of the latterto line J3 and energizing switch indicator H3moving the same io clear position. The current in this circuit alsoattracts the armature of tower indicator U giving a clear indication,stops the bell from ringing and attracts the armature of relay C3thereby extinguishing the lamp L3 Jfor the signal S3, opens the motorbattery circuit controlled' by relay C3 shunts the motorl through thefront contact of said relay and the signal moves to danger. The

return motor control it will be noted, is shunted or the motor or motorsincluded in closed shunt circuits when the clearing relays vhence twolamps are required for il z respects identical,

eign currents on the signal motors or clutches y is practicallyeliminated and the chances of interference by such foreign currentstending to cause the signals to stick in'clear or caution position whenthey should be in the danger position as when the. track relays areopened, is reduced to a negligible factor.

In Fig. 3 the circuits and operation of the system correspond in allrespects to Figs. 1 and 2 the sole difference between the two systemsbeing that in Fig. 3 two signals or semaphores are shown on the same ostand uminatmg the respective signals or sema hores. In Fig. 3 lamp L5 isin multi le Wit lamp L, lamp L6 is in multi le with amp L3, lamp L7 isinmultiple with amp L3, lamp L3 is in multiple with lamp L3, the lampsbeing thus arranged in pairs and both lam s of a pair beingsimultaneously lighted wllien the circuit conditions are as heretoforedescribed in connection with Figs. 1 and 2. It will be understood ofcourse that the two semaphores or signal arms are operated just as isnow common in the art where the double indication is desired rather thana three position indication. In this Fig. 3 the train is presumedv tooccupy the section A4, as heretofore described in connection with Fig. 1and inasmuch as the operation is in all further description is thoughtto be unnecessary, the illustration being mainly to show theapplicability of the present invention in systems requiring a pluralityof lights and in this connection it will `be understood that the numberof' lights and signals may be increased at will.

From the foregoing description it will be seen4 that failure of the lineWires between block stations will still leave an operative and safesignaling system, for instance, breakage of line wires J, J3, etc.,vwould cause the armatures of clearing relays C C3, etc., and switchindicators H H3, etc., and tower indicator U to drop and in turn thesignal governed by the said relays to change to the caution indicationland this would be the normal position in such signal. The lightscontrolled by any of the circuits would burn continuously until repairswere made and a train passing in the proper running direction wouldreceive indications in either night or day, permitting the trai-ns toproceed under caution signals but without interruption of traffic. Inother words, the system is simply transposed into a normal cautionsystem. So also should line wires K K3 etc. of common Wire M be broken,relays .1 t3 etc. would open taking away power from clearing relays C C3etc. as Well as from the switch IOO ISO

Y the proper running mally sliunted by said circuit closers indicatorsand from line relay I? and tower indicator.4 signal governed by theclearing relay to change to the caution indication and the lights wouldburn continuously as before. As in the other instance, a train passingin direction would receive a caution indication when the track relayswere closed, and in every instance, the signals `will always display"danger in rear of the trains and cannot be moved'to the caution positionuntil the train has cleared the track section. Under the conditionsstated wherein all of the line wire connections have failed,

all lamps will burn continuously and the system is transposed into anormal caution system, the signaling mechanism proper including the semahores, lights, caution motor control &c., al being operative andeilective and under the control of the track relays.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is

1. In a block signaling a paratus the coinbination with a series otpnormally closed rail 'circuits and circuit closers controlled by saidcircuits, of signaling circuits noi'- mally shunted by said circuitclosers and adapted to be established to render the signals operative bythe presence of a train on the track sections.

2. In a block signaling apparatus, the combination with a series ofnormally closed rail circuits and circuit closers controlled by saidcircuits, of'a series of signal circuits nlprut established by saidcircuit closers when the rail circuits are sliunted to render thesignals operative.

3. In a block signaling apparatus, the

combination with a series of normally closed rail circuits and circuitclosers controlled thereb of indicator and clearing circuits 7 norma lyestablished by preliminary relay in series,

said circuit closers and a series of signal circuits normally shunted bysaid circuit closers but established by said circuit closers when therail circuits are shunted to render the si als operative.

4.r In a block signa ing apparatus, the combination with a series ofnormally closed rail circuits and track relays controlled thereby, acircuit controlled by two successive track relays and including adistant and a normally closed contacts controlled by the preliminaryrelay, a combined clearing and indicating circuit including thepreliminary relay contacts and contacts controlled by a track relay,said two last mentioned circuits being interrupted when the railcircuits are shunted thereby preventing signals in rear of trains andindicators ahead of trains from clearin f and also causing signals aheadof trains to c ear when the track circuits ahead of trains are notshunted.

5. In a block signaling apparatus, the

This in turn would also cause the combination with a series of normallyclosed rail circuits and circuit closers controlled thereby, ofindicator and clearing and distant circuits normally established by saidcircuit closers and interrupted thereby when the rail circuits aresliunted to move the indicators to danger and prevent the clearing oftheblock signals.

6. In a block signaling system the combination of a series of normallyclosed an energized track circuit sections,4 circuit closers controlledthereby, distant relay circuits normally closed by 'said circuit closersand each including a distant relay and a preliminary relay embodyingshunt coils normally in series and of such resistance as to prevent theoperation of the distant relay, automatic signals having a preliminaryor caution position controlled by the track section circuit closers,circuit closers controlled by the signals to shunt the preliminary relaycoils, reduce the circuit resistance and render the distant relayoperative to clear a signal previously moved to the caution position.

7. In a block signaling system the combination ot' a series of normallyclosed and energized track circuit sections, circuit closers controlledthereby, distant rela circuits nornially closed by said circuit c osersand each including a distant relay at the home station and a preliminaryrelay at a succeeding station einbodyinr shunt coils normally in seriesand of suc-i resistance ,as to prevent the operation of the distantrelay, automatic signals havinga preliminary or caution positioncontrolled by the track section circuit closers, circuit closers closedbythe signals when in caution land clear positions to shunt the coils ofthe preliminary relay, reduce the circuit resistance and render thedistant relay at the home station operative and a clear signal operatingcircuit established by said distant relay to clear the signal when thesaid succeeding signal is in caution position.

8. In an automatic block signaling system, the combination of norniallclosed track circuit sections and inde en ent normall f open signallighting circuits controlle by t e track circuits, associated -withmechanical signals rendered visible by the closing of the lightingcircuits.

9. In an automatic railway block signaling system, the combination of aplurality of normally closed track circuit sections and a plurality ofindependent normally open signal lighting circuits each controlled bytheimmediate and next preceding track circuit sections whereby ythe signalsare lighted a section in advance of that in which a train may be locatedand extinguished only after the train has passed out ofthe immediatesection.

10. In an automatic railway block signal- IIO IIS

' track ing system, the combination of a plurality of. normally closedtrack circuit sections and a plurality of independent normally opensignal lighting circuits each controlled by two sections of trackvcircuit to light the signals during the presence of a train in eithersection.

11. In an automatic railway blocksignaling system the combination of aplurality of normally closed track circuit sections, circuit closerscontrolled thereby, normally energized relayscorresponding in number tothe track circuit sections and each controlled by two sections of trackcircuitand independent signal lighting circuits one for each relay andincluding a'circuit closer normally held open through the action of saidrelay but released to close the lighting circuit when a train is ineither of the controlling track sections.

12. In an automatic block signaling system, the combination of aplurality ot' normally closed track circuit sections, normally closedcircuit closers controlled thereby, normally energized relays one foreach section and included in a circuit controlled by two track sectioncircuit closers, normally open independent local signal lightingcircuits a circuit closer for each lighting circuit controlled by one ofsaid relays and released to light the signal lights by opening ofthe'relay circuit through the presence of a train -in either of thecontrolling track sectionsor through failure of the line wires.

.13. In an automatic block signaling system, the combination of normallyclosed track circuit sections, normally open lighting circuits, normallysliunted signaling circuits and circuit closers controlled by thetrackcircuits to close the lighting circuits and open the signal circuitshunts when the track circuits are shunted.

14. In an automatic block signaling system, the combination of normallyclosed track circuitsections, normally o pen lighting circuits, normallyshunted signaling circuits, normally closed indicator and clearing relaycircuits, and circuit closers controlled by the track circuits to closethe lighting circuits, open the shunts of the signal circuits and openthe indicator and clearing relay circuits when the track circuits areshunted.

15. In an automatic block signaling system the combination of normallyclosed track circuit sections, normally inoperative local signalcircuits, normally closed distant Aand preliminary relay circuits,distant and preliminary relays in saidI last mentioned circuits andcircuit track circuit -sections and distant relays for establishing thesignal circuits to operate the signals.

16. In anautomatic tem the combination of normally closed circuitsections, normally inoperative local caution and clear signal circuitsnorblock signaling sysdanger, track and d anger to caution closers.controlled by theV mally closed distant and preliminary relay circuits,distant and preliminary relays in said last mentioned circuits, circuitclosers operated by the track circuits for establishing the relaycircuits, circuit closers operated by the distant relay and by the trackcircuits for establishing ythe clear signal circuit, the circuit closerscontrolled b r the track circuits also operating .to establish thecaution signal circuits independently of the distant relays.

17. In an automatic block signalingsystem the combination of a plurahtyof automatic signals normally indicating danger but adapted to indicatecaution or clear and located' respectively at the entrancey to theblocks, local signal circuits for moving said signals to caution andclear positions, normally closed line circuits between stationsincluding circuit controllers for the signal circuits whereby themovement of the signal at one station is dependent upon conditionsexisting at another station and circuit control- 1ers at each stationoperated by the track section circuit for that signal circuit, and whenthe line circuits are broken or inoperative, operating to establish saidsignal circuit to hold the signal out of the danger position, butpermitting it to move to danger when the track section is occupied.

block also controlling a 1S. An automatic block signaling system Ynormally stand at stop or line circuits operating to control themovenient of said signals from or clear positions in advance of anapproaching train and also enibodying signaling circuits controlled fromthe track circuits alone when the line circuits are broken orinoperative for holding said signals normally out of'the danger positionbut permitting any signal to go to danger when the track sectioncontrolled by that signal is occupied by a train', the breaking ofwherein the signals 'the line circuits thus transpos'ing the system froma normal danger into a normal caution or clear system. f

19. In an automatic signaling system, the combination of a plurality ofautomatically controlled signals, normaiy lindicating stop, normallyclosed track circuits shunted'by a train in the immediate block section,normally closed distant control and preliminary relay circuits operatedby two sections of track circuit, normally closed indicator and clearingrelay-,circuits operated by a preliminary, and a track relay switch,normally shunted signaling circuits controlled by a clearing relayswitch to 'remove the shunt and give ower to the signal motor through animmediate track relay switch, to give a caution indication and also togive power tlirou h an additional relay switch controlle by a secondsection of track circuit and a circuit closer on the signal in advanceto give a clear indication.

IOO

IIO

ISO

"'20. In an automatic block signaling system, the combination of thetrack circuit sections including track relays a signal normallyindicating stop located at the entrance to each block section andadapted to give a plurality of indications, signal motor controlcircuits for controlling the movement 'of the signal away from stopposition and normally shunted, a clearing relay for removing the shuntfrom the signal circuit `and giving power through the track relayswitchto give a caution indication, a preliminary relay having'l twowindings and a distant relay in series therewith but at the opposite endof the distant wire, the preliminary relay being of high resistance andhaving its armature normally attracted, ,the distant relay being of' lowresistance and having its armature normally at'rest against a back stop,a circuit closer on the caution indicating mechanism for shunting partof the coils of the preliminary relay -to increase the current in thedistant wire to render the distant relay operative and a circuit closercontrolled by t e` armature of the distant relay and included in theclear signal motor control cirp distant line wire having) two relaysofdi cuit.

21. In an automatic block signaling system the combination withnormally` closed track circuits includin track relays, and signalcircuits controlle by said relays, .o a

erent resistance in series ut at opposite lends of a block section forcontrolling the clear signal circuit and both controlled by an immediateand an advance track circuit relay.

22. In an automatic block si al' system', normally closed track circuitsinc udm track relays, normally closed indicator an clearin 'relaycircuits in'multiple and each control ed by two preceding track relays,and si als controlle by said circuits.

23. n an automatic block signaling sys- Vtem the combination of'trackcircuit secnormally --closed tions, normally open lighting circuits, andclearing circuits between block stations including. relays for holdingthe lighting circuits open, whereby upon signal in advance of the breakbreaking or failure of any clearin circuit the wilI be lighted.

T5245. In a block signal system the combinationof a signal givin homeand distant indications for each' bloc section-a distant con'- trol anda preliminary relay of different resistances in series with a battery inthe same line but at opposite ends of a circuit, a circuit controlleroperated by a second home signal for shunting out a part of theresistance included in one relay when said home signal is clear, theoperation being that when all the resistance in both relays 1s in theline circuit the preliminary relay only will respond to the circuit ofthe battery, but when a 'part of the resistance of one rela is shuntedout of the circuit both relays wi l respond to the current of thebattery.

25. In an automatic signaling system, the combination of normally closedtrack circuits and normally open circuits for lightinr switch lamps,assoclated with mechanical switch signals lightedby said lamps.

26. In an automatic si aling system, the combination with norma y closedtrack circuits, normally open switch lighting circuits,

normally closed clearing circuits, all so arranged that the breakage ofany or all the controlling line wires, de-energizes the clearing rela scausing switch lamps to burn continuous y. y. y

27. In an automatic block signaling system, rthe combinationwithnormally closed track circuit sections includin track relays, andcontact lingers controlled y said relays, of signal motor circuitsnormally established through said contact fingers and broken when'therela s are de-energized and a shunt fdr the signa circuits closed by theback movement of said iin ers, whereby the ossibility of the signa sremaining at c ear when danger condltlons exlst is eliminated.

FRANK I. J. PATENALL. GEORGE H. DRYDEN.

